CA1325121C - Optical wave guides - Google Patents

Optical wave guides

Info

Publication number
CA1325121C
CA1325121C CA000568586A CA568586A CA1325121C CA 1325121 C CA1325121 C CA 1325121C CA 000568586 A CA000568586 A CA 000568586A CA 568586 A CA568586 A CA 568586A CA 1325121 C CA1325121 C CA 1325121C
Authority
CA
Canada
Prior art keywords
optical fibre
glass composition
optical
crystallites
rare earth
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA000568586A
Other languages
French (fr)
Inventor
Benjamin James Ainslie
Susan Patricia Craig
Steven Terrence Davey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
British Telecommunications PLC
Original Assignee
British Telecommunications PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by British Telecommunications PLC filed Critical British Telecommunications PLC
Application granted granted Critical
Publication of CA1325121C publication Critical patent/CA1325121C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C4/00Compositions for glass with special properties
    • C03C4/12Compositions for glass with special properties for luminescent glass; for fluorescent glass
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C10/00Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
    • C03C10/0009Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing silica as main constituent
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C4/00Compositions for glass with special properties
    • C03C4/0071Compositions for glass with special properties for laserable glass

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Glass Compositions (AREA)
  • Lasers (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
  • Laser Surgery Devices (AREA)

Abstract

ABSTRACT

OPTICAL WAVE GUIDES

Glass fibre suitable for use as the core in fibre lasers and/or amplifiers has a core which consists of a continuous glass phase and a disperse phase of crystallites. The preferred crystallites are the oxides and phosphates of rare earth metals, eg Nd203 and NdP5014. The small size concentration and distribution of the crystallites keeps the attenuation down to acceptable levels.

Description

-1- 132~121 OPTICAL WAVB GUIDBS
8T PATENT CAS~ A23684 (~UBS)(0811P) This invention relates to wave guides ~hich have properties appropriate for use in lasing devices. Thus they may be used, for example, as components of signal sources and signal amplifiers in optical telecommunications systems.
Because of their potential importance in teleco~munications, there has been substantial interest in devices implemented in fibre configurations, eq fibre lasers and fibre a~plifiers. ~uch of this wor~ has utilised glasses vhich contain ions with laser properties, eg Nd3+ ions. These ions are incorporated as part of the glass, eg they are incorporated in an amorphous phase or a solid solution. These special glasses constitute the path region of optical waveguides, eg the core of an optical fibre. During use, the device is pumped to produce a population inversion of the active ions so that lasing occurs.
. 20 It has only been possible to ma~e glass which contains a limited concentration of active ions homogeneously dispersed throughout the glass before phase changes ta~e place in the glass. It is desirable to increase their ~f.~ concentration, eg in order to make high gain short length . 25 devices. Weaver, Stewart and Neilson, in ~Journal of the :~- American Ceramic society" vol 56 no 2 published February ~` 1973 at pages 68 to 72 discuss the lasing parameters in a r phase separated glass. They report that small amounts of phase separation increased the lasing efficiency but in ` :` 30 general efficiencies decreased. Auzel et al in French '. ~

1~2~21 patent specification 2238679 and in the "Journal of the Electrochemical Society" Vol. 122, No. 1 published January 1975 at pages 101-107 discuss rare earth doped vitroceramics for infrared up-conversion.
According to this present invention, an optical wave guide with fluorescing or lasing properties has a path region formed of a glass composition comprising a continuous glass phase having dispersed therein crystallites with fluorescing or lasing properties.
It has surprisingly been found that wave guides of this nature have properties useful for lasers (and optical amplifiers). It would be expected that the disperse phase in the path region would cause scatter and hence give rise to unacceptably high attenuations at both pump and signal wavelengths. However, the size and concentration of the crystallites can be controlled so that the scatter attenuation is kept to an acceptably low level, e.g. below 10 dB/m and preferably below 1 dB/m based on fibre made from the glass. It will be appreciated that the use of a : . .
disperse phase avoids solubility limits, whereby higher concentrations of active lasing sites are possible.
According to a further aspect of the present invention there is provided an optical fibre with fluorescing or lasing properties which fibre has a core of a first glass composition and a cladding surrounding the core, the cladding being formed of a second glass composition which has a lower refractive index than the first glass composition wherein the first glass composition 132~121 comprises a continuous glass phase having dispersed therein crystallites with fluorescing or lasing properties.
According to a still further aspect of the present invention there is provided an optical waveguide suitable for use as an optical laser or amplifier, the waveguide comprising: a core having a continuous glass composition first phase made from a mixture of at least two different glass forming materials to provide the continuous glass composition phase having a first refractive index; the core also having crystallites of rare earth metal oxides or phosphates with fluorescing properties in a second crystalline phase dispersed with the first phase; and a cladding layer of glass composition disposed about the core and having a second refractive index lower than the first refractive index.
A yet further aspect of the present invention provides an optical fibre amplifier comprising (i) input means for connection to a first telecommunications transmission fibre for the receipt of attenuated signals;
(ii) output means for connection to a second telecommunications transmission fibre for the output of amplified signals; (iii) an optical fibre with fluorescing or lasing properties which fibre has a core of a first glass composition and a cladding surrounding the core, the cladding being formed of a second glass composition which has a lower refractive index than the first glass composition wherein the first glass composition comprises a continuous glass phase having dispersed therein crystallites 2a ~.

132~121 with fluorescing or lasing properties, which optical fibre interconnects the input to the output, whereby the lasing properties of the crystallites in the optical fibre provide means for amplifying optical signals travelling in the optical fibre; and (iv) pump means connected to (iii) for the provision of pump frequency radiation so as to excite the crystallites and provide the amplification.
It has also been reported that lasing ions can affect one another. Thus, even when solid solutions are chemically stable, active sites in close proximity interact adversely with one another and the performance of the laser is poor, a phenomenon known as concentration quenching. The crystallites can be made to operate by a different mechanism and the problem be avoided. Thus the use of crystallites gives good lasing action.
The (conventional) silica based glasses are suitable for use as the continuous phase. While the primary component of these glasses is sio2 other components are often present, especially GeO2 to increase the .

~3~ 132~121 refractive index. Other dopants may also be present, eg to adjust melting points to facilitate lower processing temperatures and increase choice of host glass, eg P205, F~ A123 The chemical species suitable for the crystallites includes rare earth oxides and phosphates. The phosphates conveniently have the forDula X'P5014 where X' represents one or more rare earth elements. The oxides are xn2o3 where X~ represents one or more rare earth elements. The following are quoted as specific examples of suitable chemical species:
NdP5014 LaP5014 CePsO14 : 15 LaxNd(l-x)p5ol4 where x is between 0 and 1 CeyNd(l-y)p5ol4 where y is between 0 and 1 [XNzNd(l-z)]203 where z is 0 to 1 inclusive . and X" is selected from ; ~ La, Gd and Y.

:
- Since the disperse phase will, at some time in its history, have been in chemical equilibrium with the continuous phase, the continuous phase will usually contain the rare earth as a dissolved species.
. 25 This invention also includes optical waveguides in the form of optical fibre, which may be either multimode or - monomode at the signal wavelength, wherein the core is made of a glass composition as described above and the cladding is made of a different glass composition having a lower refractive index.
For e D ple, a fibre comprises a cladding consisting essentially of SiO2 ~ith a core consisting essentially of SiO2 + GeO2 (to raise the refactive index) and the ~:

~4~ 132~121 dispersed lasing dopant. ~o minimise attenuation it would be desirable for the fibre to consist of, ie. to consist only of, the components mentioned. However, it is usually convenient to introduce processing additives, eg. P20s s and F, and this can be done without changing the essential properties of the glass.
The glass composition which forms the path region of a wave guide according to the invention is conveniently made by preparing the crystallites from a precursor o composition, eg. a single phase composition. The preparation may involve the simple precipitation of a dissolved species, eg. the precipitation of a dissolved rare earth oxlde from an oxide glass such as SiO2 +
GeO2. Alternatively it may involve the reaction of precursors to give, a new species, eg. the reaction of oxides with P205 to yield a precipitated phosphate ~odern processes for making optical fibre usually include the preparation of the various glasses by deposition from a vapour phase oxidation reaction. The deposition is controlled to produce a suitable configuration for the mechanical preparation of the fibre. Typical preparation reactions include:

(i) SiC14 + 2 = SiO2 + 2C12 (ii) GeC14 + 2 = GeO2 + 2C12 (iii) 4XC13 + 2 = 2x2o3 + 6C12 (where X is a rare earth) Other reactants may also be used, eg volatile organo-metallic compounds which convert to the oxide, eg at high temperature and in the presence of oxygen.
Various embodiments of the invention will now be described by way of example ~ith reference to the accompanying drawing in which:
' , ~ . . . .

~5~ 1325121 Figure 1 illustrates, diagrammatically, NCVD used to prepare fibre according to the invention.
Figure 2 illustrates a source of rare earth for use in - the NCVD illustrated in Figure 1, and Figure 3 illustrates an amplifier including fibre according to this invention.
Figure 1 illustrates a conventional NCVD process in cj~ vhich a substrate tube 10 is rotated ln a glass blowing lathe (not shown~ and a reactant gas which comprises 2 and SiC14 together with dopants such as POC13 (to .. . .
adjust meltinq point) and GeC14 (to increase the refractive inde~). A short segment of the tube, about 2cm ` long, is heated to about 1600C by means of a travelling flame 11. In this segment chlorides are converted into , oxides which deposit in the form of a porous ring downstream of the flame 11. As the flame traverses the deposit fuses to form a thin layer of non-porous glass on the inner surface of the substrate tube 10.
Upstream of the deposition zone 14, the substrate tube 10 iS formed into a source chamber 15 which contains a glass spcnge 12 which is impregnated with the chloride of a rare earth metal. An independent burner 13 is provided to heat the source chamber 15.
, ;; As shown in Figure 2 the sponge 12 comprises an outer ~: ~ 25 layer 20 of non-porous glass and an inner layer 21 of ` spongy glass. The inner layer 21 is impregnated with the rare earth metal chloride. The sponge was prepared by depositing a porous layer on the inner surface of a substrate tube about lm long using NCVD technique as described above. The sponge was soaked with an alcoholic solution of the hydrated chloride. Excess solution was removed and the solvent was evaporated. Water of .

' - `
;

crystallisation was removed by heating in the presence of chlorine. The long tubular sponge was cut into segments about 2 cm long.
The sponge 12 as well as its preparation and use is described in our United States Patent No. 4,799,946.
Using the MCVD technique mentioned above conventional reactants, eg SiCl4, POCl3, CCl2F2 and 2~ were passed into the bore of a substrate tube and several glass layers were deposited on its inner surface. These layers constituted the precursor of the cladding of a fibre and they had the chemical composition of SiO2 glass doped with P2Os and F as melting point modifiers.
Thereafter the reactants were changed to SiCl4, POCl3, GeCl4 and 2 to deposit several layers constituting the precursor of the core of the fibre. During this deposition independent burner 13 was used to volatilise NdCl3 into the reactant stream. Thus the chemical composition of the core precursor was SiO2 glass doped with GeO2, P2Os and Nd3'. Finally the tube was collapsed and drawn into fibre in the conventional way. Because there was a high concentration of rare earth, the oxide precipitated as a colloid at some stage during the process.
The attenuation of the fibre was measured at wave lengths of interest in the band 500 to 1700 nm. There are two mechanisms which cause the measured attenuation, namely absorption (by rare earth ions) and scatter. Both the continuous phase and the dispersed particles contribute to the absorption but only the dispersed particles cause scatter. The following attenuations were recorded:-., ~
.~, ` -7- 132~121 Wave length (nm) Attenuation (dB/m) - s 1060 below 0.1 ,, .
800nm is the pump wave length (and 1060nm is the ` signal wave length). Since Nd3+ absorbs at its pump wave there is a high (50dB/m) attenuation. Nd3+ does o not absorb at its siqnal wave length and the low ; attenuation (below O.ld~/m) is due to scatter.
~ This attenuation is acceptable for a laser device - because using these high concentrations of lasing materialthe length of a device is likely to be less than lm and ~ l5 a~most certainly less than lOm. In any case the gain : outweighs the loss and, therefore, a small increment in the length of the device compensates for the loss.
It is surprising that the two-phase system produces fibre which is low in loss. It is believed that the attenuation is low because the particle size is low, eg ~- less than 0.1 of the pump wavelength. We have measured particle sizes typically 20nm in diameter embedded in the glass matrix using transmission electron microscopy. The average concentration of Nd3+ in the core was measured to be approxlmately 103ppm by weight.
We have measured the fluorescence spectrum of this core glass and observed sharp emission spikes superimposed on the broad fluorescence bands. This, we believe, is due to fluorescence from the crystallites (the sharp peak component) and from the Nd3+ ions homogenously distributed in the glass (broad component).

.

.''"'' .

,,,r~
'?

-8- 132~121 , .
In a second ehample ve have made Er3~ doped fibre in a way very similar to that described above, but BrC13 has been used lnstead of NdC13. Uslng a SiO2-P2Os-GeO2 host glass an average concentration of 7 x 103ppm ~r3~ resulted. Visual inspection of the preform under intense white light illumination showed that white light could be observed from the side of the preform core. When dra~n into fibre, the scatter loss was measured at 750nm (where ~r3~ does not absorb) and was found to be very low (less than 0.2db/m), but the absorption bands were very strong:
Wave length (nm) Attenuation (dB/m) 810 ll A strong band located at 520-530nm was too intense to be resolved.
An alternative method of making fibre by hCVD (not illustrated) comprises depositing the cladding precursors conventionally and then depositing core precursors without the rare earth and at a low temperature so that the core precursors remain porous. After cooling, the porous layers of the cladding precursor are soaked with an alcoholic solution of a rare earth halide. The excess liquid is drained away, the solvent evaporated and the chloride dehydrated by heating with a mixture of C12/O2. At this stage the porous layer is fused and thereafter collapsed. Drawing proceeds as in the first described technique.
Figure 3 illustrates an arrangement to demonstrate the amplifying utility of fibre according to the invention.
Fibre 30, having a core consisting of rare earth dopant crystallite embedded in a glass matrix, is ~ connected, at a junction 36, to (non-lasing) optical :. , .

132~121 , g fibres 31 and 32. Fibre 32 is coupled to a laser 34 which ` provides pump frequency into the core of fibre 30. fibre 31 is connected to a laser 33 which generates an optical signal.
The output end of fibre 30 is welded to a fibre 37. Detector 35 is coupled to the end of fibre 37.
In the use of the device, pump 34 causes a population inversion in the rare earth atoms contained in the core of fibre 30 and photons of signal, from laser 33, stimulate emission from the inversion whereby amplified signals pass into fibre 37 for detection in detector 35.
We wish to draw attention to two United States patents which were granted to British Telecommunications plc and relate generally to optical fibres:
: 15 United States Patent No. 4,799,946 relates to the use of glass sponges to incorporate rare earths into optical fibre; and United States Patent No. 4,974,933 relates (among other things) to optical fibres which contain colloidal particles in its core and/or cladding.

,~

Claims (29)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1 An optical wave guide with fluorescing or lasing properties which has a path region formed of a glass composition wherein said glass composition comprises a continuous glass phase having dispersed therein crystallites with fluorescing or lasing properties and wherein said crystallites are present in sufficient amount to support said fluorescing or lasing.
2 An optical wave guide according to claim 1, wherein the crystallites comprise oxides and phosphates of rare earth metals.
3 An optical fibre with fluorescing or lasing properties which fibre has a core of a first glass composition and a cladding surrounding said core, said cladding being formed of a second glass composition which has a lower refractive index than said first glass composition wherein said first glass composition comprises a continuous glass phase having dispersed therein crystallites with fluorescing or lasing properties.
4 An optical fibre according to claim 3, which has a scatter attenuation of less than 10dB/m at signal wave length.
An optical fibre according to claim 4, wherein the scatter attenuation is less than 1dB/m.
6 An optical fibre according to claim 3, wherein the crystallites are selected from the group consisting of the oxides and phosphates of rare earth metals.
7 An optical fibre according to claim 6, wherein the oxides have the formula X"2O3 where X" represents rare earth metals.
8 An optical fibre according to claim 6, wherein the phosphates have the formula X'P5O14 where X' represents rare earth metals.
9 An optical fibre according to claim 6, wherein the rare earth metals are selected from Nd, La, Ce, Gd, and Y.
An optical fibre according to claim 6, wherein the crystallites are selected from:
Nd P5O14 La P5O14 Ce P5O14 LaxNd(1-x)P5O14where x is between 0 and 1 CeyNd(ly)p5O14where y is between 0 and 1 [X''zNd(1-x)]203where z is 0 to 1 inclusive and X" is selected from La, Gd, and Y.
11 An optical fibre according to claim 6, wherein the glass composition of the core contains between 1ppm and 105 ppm by weight of the rare earth element.
12 An optical fibre according to claim 3, wherein the continuous phase of the first glass composition consists essentially of a mixture of SiO2 and GeO2.
13 An optical fibre according to claim 12, wherein the second glass composition consists essentially of SiO2.
14 A laser device which comprises an optical wave guide according to claim 1 and means for providing pump frequency radiation into the path region thereof.
An optical amplifier which comprises a laser device according to claim 14, means for providing an input optical signal into its path region and means for extracting amplified signals from its path region.
16 An optical waveguide suitable for use as an optical laser or amplifier, said waveguide comprising:
a core having a continuous glass composition first phase made from a mixture of at least two different glass forming materials to provide said continuous glass composition phase having a first refractive index;
said core also having crystallites of rare earth metal oxides or phosphates with fluorescing properties in a second crystalline phase dispersed within said first phase;
and a cladding layer of glass composition disposed about said core and having a second refractive index lower than said first refractive index.
17 An optical waveguide as claimed in claim 16 wherein said core contains less than 105 ppm by weight of said rare earth element.
18 An optical waveguide as claimed in claim 16 wherein said first phase of the core comprises both GeO2 and SiO2.
19 An optical waveguide as claimed in claim 16, wherein said first phase of the core comprises at least three components: GeO2, P2Os, and SiO2.
An optical fibre amplifier comprising:
(i) input means for connection to a first telecommunications transmission fibre for the receipt of attenuated signals;
(ii) output means for connection to a second telecommunications transmission fibre for the output of amplified signals;
(iii) an optical fibre with fluorescing or lasing properties which fibre has a core of a first glass composition and a cladding surrounding said core, said cladding being formed of a second glass composition which has a lower refractive index than said first glass composition wherein said first glass composition comprises a continuous glass phase having dispersed therein crystallites with fluorescing or lasing properties, which optical fibre interconnects said input to said output, whereby the lasing properties of the crystallites in said optical fibre provide means for amplifying optical signals travelling in the optical fibre;
and (iv) pump means connected to (iii) for the provision of pump frequency radiation so as to excite said crystallites and provide said amplification.
21 An optical fibre amplifier according to claim 20, wherein the crystallites are selected from the group consisting of the oxides and phosphates of rare earth metals.
22 An optical fibre amplifier according to claim 21, wherein the oxides have the formula X"203 where X" represents rare earth metals.
23 An optical fibre amplifier according to claim 21, wherein the phosphates have the formula X'P5014 where X' represents rare earth metals.
24 An optical fibre amplifier according to claim 21, wherein the rare earth metals are selected from Nd, La, Ce, Gd, and Y.
An optical fibre amplifier according to claim 21, wherein the crystallites are selected from:
Nd P5014 La P5014 Ce P5014 LaxNd(1-x)P5014where x is between 0 and 1 CeyNd(1y)P5O14where y is between 0 and 1 [X"zNd(1-x)]203where z is 0 to 1 inclusive and X" is selected from La, Gd, and Y.
26 An optical fibre amplifier according to claim 21, wherein the glass composition of the core contains between 1ppm and 105 ppm by weight of the rare earth element.
27 An optical fibre amplifier according to claim 20, wherein the continuous phase of the first glass composition consists essentially of a mixture of SiO2 and GeO2.
28 An optical fibre amplifier according to claim 27, wherein the second glass composition consists essentially of SiO2.
29 An optical fibre amplifier according to claim 20, wherein said optical fibre is 1 metre or less in length.

An optical fibre amplifier according to claim 20, wherein said optical fibre is 10 metres or less in length.
CA000568586A 1987-06-11 1988-06-03 Optical wave guides Expired - Fee Related CA1325121C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8713698 1987-06-11
GB878713698A GB8713698D0 (en) 1987-06-11 1987-06-11 Glass compositions

Publications (1)

Publication Number Publication Date
CA1325121C true CA1325121C (en) 1993-12-14

Family

ID=10618763

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000568586A Expired - Fee Related CA1325121C (en) 1987-06-11 1988-06-03 Optical wave guides

Country Status (8)

Country Link
EP (1) EP0294977B1 (en)
JP (1) JPH0776801B2 (en)
AT (1) ATE69597T1 (en)
CA (1) CA1325121C (en)
DE (1) DE3866288D1 (en)
ES (1) ES2027380T3 (en)
GB (1) GB8713698D0 (en)
GR (1) GR3003859T3 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5282079A (en) * 1988-06-10 1994-01-25 Pirelli General Plc Optical fibre amplifier
AU625144B2 (en) * 1989-10-31 1992-07-02 Fujitsu Limited Production method for optical fiber base material
US5253258A (en) * 1991-10-17 1993-10-12 Intellectual Property Development Associates Of Connecticut, Inc. Optically encoded phase matched second harmonic generation device and self frequency doubling laser material using semiconductor microcrystallite doped glasses
GB2289159B (en) * 1991-10-17 1996-03-13 Intellectual Property Dev Ass Frequency doubling laser material
FR2714046B1 (en) * 1993-12-16 1996-03-08 France Telecom Glass-ceramic materials, in particular for lasers and optical amplifiers doped with rare earths and process for manufacturing such materials.
FR2755309B1 (en) * 1996-10-31 1999-01-15 Auzel Francois PROCESS FOR THE MANUFACTURE OF A VITOUS MATERIAL DOPED AND INTENDED FOR THE AMPLIFICATION OF OPTICAL OR LASER WAVES
DE10163553B4 (en) * 2001-12-21 2008-01-17 Schott Ag Phase-separated glasses and their use
KR100776830B1 (en) * 2006-06-29 2007-11-28 고려대학교 산학협력단 Two-photon dyes for real time imaging of lipid rafts
KR101114424B1 (en) * 2011-04-22 2012-03-13 세명대학교 산학협력단 Piezoelectric ceramics composition

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2238679B1 (en) * 1973-07-26 1978-06-30 Auzel Francois
DE2417963B1 (en) * 1974-04-11 1975-08-07 Max Planck Gesellschaft Light guide
JPS56155035A (en) * 1980-04-25 1981-12-01 Nippon Telegr & Teleph Corp <Ntt> Light transmitting fiber and its preparation
JPS60230105A (en) * 1984-04-27 1985-11-15 Dainichi Nippon Cables Ltd Optical fiber
WO1986007348A1 (en) * 1985-06-03 1986-12-18 Hughes Aircraft Company Method for introducing dopants in optical fiber preforms

Also Published As

Publication number Publication date
JPH0776801B2 (en) 1995-08-16
DE3866288D1 (en) 1992-01-02
GB8713698D0 (en) 1987-07-15
EP0294977A1 (en) 1988-12-14
GR3003859T3 (en) 1993-03-16
JPS642005A (en) 1989-01-06
ATE69597T1 (en) 1991-12-15
ES2027380T3 (en) 1992-06-01
EP0294977B1 (en) 1991-11-21

Similar Documents

Publication Publication Date Title
US5278850A (en) Wave-guiding structure with lasing properties
US6889528B2 (en) Process of making rare earth doped optical fiber
CA2051104C (en) Quartz glass doped with rare earth element and production thereof
EP0313209B1 (en) Optical fibre with fluorescent additive
EP0565439B1 (en) Manufacturing method for erbium-doped silica glass optical fibre preforms
EP0272258B1 (en) Fabrication of optical fibres
WO1992010014A1 (en) A method and apparatus for amplifying an optical signal
JP4141956B2 (en) Manufacturing method of optical fiber doped with rare earth elements
CA1325121C (en) Optical wave guides
US4936650A (en) Optical wave guides
WO2002060830A1 (en) A process for making rare earth doped optical fibre
US5260816A (en) Optical amplifier with erbium-doped fiber
JPH012005A (en) optical waveguide
CA2481204C (en) A method of fabricating rare earth doped optical fibre
US20020114607A1 (en) Active optical fibre doped with rare earth elements
WO2001044837A2 (en) Optical gain fibers
DiGiovanni Fabrication of rare-earth-doped optical fiber
JP3475109B2 (en) Rare earth element doped glass
WO2004028992A1 (en) Tellurite glass, optical fibre, optical amplifier and light source
Taylor et al. Fabrication and Optical Characterization of Doped Germanosilicate Fibres
WO2001076024A1 (en) Active optical fibre doped with rare earth elements
Townsend et al. Optical fibre amplifiers
ZA200403772B (en) A process of making rare earth doped optical fibre.

Legal Events

Date Code Title Description
MKLA Lapsed